Thanks to a special thin-fin design, the cut-off frequency of a germanium-waveguide photodiode has now reached 265 GHz, into the realm of the best performing III–V high-speed devices. The development suggests that cost-effective silicon-compatible technology can now offer exceptional performance for use in optical communications.

See Lischke et al. and Virot

Artistic view of random number generation — represented by a roll of the dice — using parametrically driven optical solitons in a nonlinear fibre resonator with competing quadratic and cubic nonlinearities.

See Englebert et al.

Artistic impression of a frequency reference optical chip based on a suspended nanoscale silicon nitride waveguide that is surrounded by a vapour of rubidium atoms. The interaction between the waveguide’s evanescent field and the atoms provides the feedback necessary for highly precise frequency stabilization, enabling a 780 nm tunable laser to reach a frequency instability of less than 50 kHz.

See Zektzer et al.

Artistic impression of red, green and blue lasers based on solution-processed colloidal quantum dots applied to a thin, flexible substrate.

SeeJung et al.

Artistic impression of near-field terahertz nanoscopy probing the femtosecond dynamics of interlayer excitons (red-blue bubble structures) in van der Waals heterobilayers (grey spheres).

See Huber et al.

Artistic impression of the generation of pairs of indistinguishable entangled photons on the edge of a two-dimensional array of ring resonators arranged in a non-trivial topology (represented by a donut).

See Mittal et al.

The image depicts a simulated intensity distribution of a scattering invariant mode (SIM) propagating through a thin layer of disordered material. The defining property of SIMs is that their output pattern is identical to the case of free space propagation. As shown in this issue, SIMs can be realized experimentally in much thicker materials that scatter light strongly.

See Mosk et al.

Artistic impression of optical computing performed by modulating the incident light with layers of diffractive structures, comprised of programmable liquid crystal array. A photodetector array then converts diffracted photons into electrons to realize a reconfigurable optoelectronic processor.

See Dai et al.

The introduction of two-dimensional spatial gain and loss into a photonic crystal laser leads to high-peak-power and short-pulse operation with a narrow beam divergence.

See Noda et al.

Artistic impression of nanoimaging of molecular vibrations coupled to phonon polaritons (blue wave) in a thin layer of hexagonal boron nitride. Nanoimaging is performed by recording the light scattered from a sharp metal tip that is scanned across the sample surface.

See Hillenbrand et al.

Doping perovskite nanocrystals with guanidinium is shown to supress defects and improve radiative recombination, resulting in green LEDs that are more efficient and brighter.

See Lee et al.

Image of a quantum optical chip wire-bonded to an electronics chip to form a homodyne detector for measuring squeezed light. This approach leads to more scalable and higher performance devices for quantum information processing.

See Matthews et al.